The Catholic Church is in the midst of an existential crisis. Can the church be changed — modernized into harmony with evolving norms on justice and mercy? Or must religious doctrine remain the same forever more?

A convert to the church (along with the rest of his family) when he was a teen, Douthat describes himself, like a character in a mid-20th-century Catholic novel, as "the good bad Catholic or the bad good one, whose loyalty was stronger than his faith and whose faith was stronger than his practice, but who didn't want the church to change all the rules to make his practice easier because then what would really be the point?"

The point, for Douthat, is the tension itself. Indeed, "the conflict between what I professed and how badly I fell short was part of what made the profession seem plausible, because a religion that just confirmed me in my early-21st-century way of life couldn't possibly be divinely revealed."

Catholicism is about the capital-T Truth — and the truth is verified by its timelessness, by the fact that on the level of fundamental dogmas and doctrines about the character of God and the moral and spiritual destiny of humanity, the institution of the church does not, indeed cannot, change or evolve, because those dogmas and doctrines are founded on divine revelation. If that makes it harder to be a Catholic as human culture changes around the institution, that is itself a sign that the revelation was real — the rock on which Jesus Christ himself empowered St. Peter to construct his church roughly 2,000 years in the past.

It's Douthat's emphasis on eternal truth, divine revelation, and striving to live up to and falling short of reaching fixed, permanent standards that marks him as a conservative, both politically and theologically. And it's his status as a theological conservative that makes To Change the Church: Pope Francis and the Future of Catholicismso stimulating and fruitful as a provocation — but also so ultimately unpersuasive as an indictment of the current pope.

Douthat claims that Pope Francis is a theological liberal, though of a particular type — namely one whose liberalism follows first and foremost from the fact that he is a member of the Society of Jesus (a Jesuit). The members of the Jesuit religious congregation tend to combine fervent faith in the life, words, deeds, and salvific message of Jesus Christ with a tendency to de-emphasize the letter of church dogma and doctrine. This tendency grows out of the order's long history of missionary work and the felt need to avoid conflicts and antagonism with potential converts in foreign cultures.

This distinctive approach to the message of the church can be seen in the pope's frequent denunciation of conservatives who get hung up, like the Pharisees in the Gospels who obsess about obeying the letter of the law, on punctilious obedience of doctrinal rules. The proper response to this problem is not necessarily for the church as a whole to soften or change its doctrines but rather for priests to diverge from them selectively in their capacity as pastors tending to their flocks.

So, just as a 17th-century Jesuit missionary bringing the good news of Christ's message to the indigenous population of Canada or the rural villages of Japan might emphasize certain aspects of the faith and de-emphasize others in order to encourage understanding and receptiveness to the message, so a modern-day priest ministering to a parish full of people who fail to uphold various aspects of church teaching, especially on sex and marriage, will find it more effective to refrain from enforcing every element of doctrine. The alternative to such flexibility is to drive people away from Jesus and his church in droves.

In Douthat's telling, Pope Francis convened the Synod on the Family in 2015 in the hope that the church's bishops would endorse something very much like this Jesuitical stance toward doctrine on one issue in particular: the permissibility of Catholics who've been divorced and remarried without having their first marriages annulled receiving the sacrament of Communion during Mass. Because Catholic doctrine holds that marriage is indissoluble, remarrying without an annulment is tantamount to living in a state of adulterousness toward one's original spouse, which is a grave sin. And taking part in Communion while in a state of grave sin (while showing no sign of an intent to cease sinning) is forbidden. Hence Catholic doctrine mandates that civilly divorced and remarried Catholics are ineligible to receive Communion.

Encouraged to some extent by a coterie of liberal European clerics, Francis seems to have thought the assembled bishops from around the world might be open to relaxing this stricture, explicitly giving priests in different countries, dioceses, and parishes the freedom to dispense Communion to parishioners they deem to be doing their best to live morally upstanding lives, even if they fail to conform to church teaching in this one respect. But several more conservative bishops, mainly from North America and Africa, strongly opposed the reform. Eventually, the pope was forced to relegate the idea to a single, somewhat ambiguous footnote buried in Amoris Laetitia, the apostolic letter published at the conclusion of the Synod.

There are many things about Francis' pontificate that trouble conservative Catholics, but nothing comes close to matching their disdain for the pope's move to circumvent more conservative bishops and accomplish what is effectively a stealth change in doctrine by planting a statement in a papal document that functions as an ecclesiastical wink, granting priests permission to disregard church teaching while simultaneously providing the pontiff with plausible deniability.

In Douthat's view, this papal encouragement of clerical laxity on a doctrine founded on the explicit words of Jesus himself (Matthew 19:5-10; Mark 10:2-12) will either intensify the regional and ideological divisions that opened up in the aftermath of the Second Vatican Council, perhaps ending in outright schism, or else it will lead to the spread of theological liberalism. The latter, as we know from the experience of numerous Protestant denominations, tends to be correlated with demographic decline, as young people raised in a watery faith quickly drift away from the church upon reaching adulthood. Either way, the consequences for Catholicism will be bad.

Douthat no doubt believes this, and he may well be right — even though the experience of the Eastern Orthodox churches, which have managed both to survive and to stave off theological liberalism while also permitting divorces and (nonsacramental) second marriages, gives compelling reason to be skeptical. (The forces driving ideological polarization and the demographic decline of religious observance across a good part of the globe are far bigger than an allegedly heretical footnote buried in an apostolic letter.)

I'm inclined to suspect such worries matter less to Douthat than the consequences of potential doctrinal innovation on his own faith. If doctrine can change, Douthat thinks, then we have reason to doubt the veracity of the divine revelation on which it is based. The logic of the position makes perfect sense. (After all, why wouldn't God have revealed the less stringent teaching two millennia ago rather than wait until the early 21st century?) But is it psychologically persuasive?

The permanence and stability of church teaching may be one sign that a founding revelation is authentic. But it is hardly a sufficient one. Surely it's equally or even more essential for the teaching to display attributes we can recognize as divine. Yes, theologians and apologists tell us that God's ways are mysterious, transcending the merely human understanding of justice. Yet it's also the case that a God whose revelations were utterly mysterious or whose actions appeared gratuitously cruel or deeply disconnected from human notions of moral righteousness would arouse little love and ultimately inspire little faith.

Changes in doctrine may sow some doubts among the faithful, but nowhere near as many as are likely to be spawned by the burgeoning sense that some of the institution's foundational teachings lack both justice and mercy. It's true that standards of justice and mercy change over time, along with our expectations from the divine. But it's also true that contemporary standards of justice and mercy are very much those of a Christian civilization struggling to apply some of Jesus' most stringent moral teachings ever-more fully to our public and private lives.

The church, buffeted by competing and even contradictory demands both to remain fixed and to adapt to changes in moral opinions over time, faces difficult challenges. Pope Francis' somewhat awkward moves around doctrines touching on marriage, divorce, and Communion are one possible response, and they may not be as prudent or wise as they should be. But that doesn't relieve the church of the need to propose some response.

The alternative isn't blissful repose in a timeless revelation. It's the stubborn adherence to dead rules on the part of a dwindling flock more attached to consistency than justice and mercy.